1. Field of the Invention
The present invention relates to a system that has the function of monitoring and diagnosing various object devices installed in particularly remote places.
2. Description of the Related Art
In recent years, monitoring systems have been developed, which monitor various object devices, such as elevators, installed in remote places. A monitoring system of ordinary type has monitoring devices and communications lines. The monitoring devices are connected to the apparatuses to monitor. The communications lines are provided to achieve communication with the monitoring devices. In the monitoring system, the abnormality, the operation data about each object device monitored, collected by one monitoring apparatus, is received through communications lines. From the data thus received, abnormality, if existing in any device monitored, can be detected from the data thus received.
Monitoring/diagnostic systems have been proposed, each capable of not only detecting abnormality in any object device, but also diagnosing the problem in the object device. Such a system is disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication No. 2003-238041. The system disclosed in this prior-art reference has a monitoring center that performs remote monitoring of elevators to collect information that may be used to make such a maintenance plan the users of the elevators can avoid damages and losses they may otherwise have if the elevators should stop operating due to an accident.
The monitoring center collects information from each monitoring device at regular intervals. The information includes the operation data and the component-replacement data, both concerning the object device monitored by the monitoring device. Using the information thus collected, the monitoring center performs a multivariate analysis on a degradation mode in which each elevator component operates until its lifetime expires. Based on the results of this analysis, the monitoring center calculates the best possible inspection interval. The analysis of the degradation mode uses various operation data items such as the load on each component, ambient temperature, humidity, operating speed, and rotations per unit time, and the like. More specifically, the parameter indicating the degradation of each component is extracted by means of multivariate analysis, the degradation tendency of the component is derived from the parameter extracted and the operation data, and an inspection interval optimal for the component is inferred from the degradation tendency. The optimal inspection interval thus obtained is utilized to formulate a maintenance plan.
In the conventional monitoring/diagnostic system, the monitoring center collects, at prescribed intervals, the operation data and the component-replacement data from the monitoring devices and some maintenance stations, and then infers, from these data items, the remaining part of the lifetime of every component of each object device monitored. Usually, the system needs to monitor many object device installed in remote places and to diagnose the object devices for possible problems in them. If so many object devices are monitored, how the operating state of each apparatus changes can hardly be detected quickly in order to diagnose the apparatus efficiently, particularly if the change is fast, merely by collecting the operation data and component-replacement data from each object device and by inferring the remaining lifetime thereof.